It is known to fabricate bathtubs and the like by thermoforming rigid thermoplastic shells and bonding the shells together such as described in U.S. Pat. No. 5,494,718. As described in that patent, it is desirable to eliminate methods using spraying techniques which are essentially manual in the formation of bathtubs and wherein a curing period is desirable. With such spraying methods, volatile organic compounds are emitted and this is of course hazardous to the health of people in the immediate environment of the manufacturing process. That patent is primarily concerned with the reduction in the wall thickness of a thermoformed vessel by the use of a reinforced cradle. They attempt to eliminate volatile organic compound emissions and provide easy recycling without sacrificing rigidity of the bathtubs. As described, it is also desirable to reduce flammability in the manufacturing process and smoke emissions which are hazardous. This patent is primarily concerned with the support formed of a glass fiber reinforced thermoplastic shell having a specific flexural modulus. The fibers are also short glass fibers which are hazardous during the shell fabrication process and disposal. When fabricating bathtubs with glass fiber coatings, it is necessary to test each bathtub for air and water leakages for the reason that there are often air pin holes in fiberglass coatings and this can be problematic during use. Also, by making bathtubs using thermoformed shells, the total weight of the bathtub is reduced as compared with conventional methods using fiberglass. This also results in a reduction in transportation cost as well as providing easier handling of the material due to its lighter weight. Also, the new process of manufacturing poses a reduced fire hazard and accidents to the workforce as there is less manipulation and mechanization. There is also acetone released in the fiberglass coating manufacturing process and this is hazardous to human health.